Method and apparatus for formation pressure testing



Feb. 13,' 1940. T, v, MQORE y `2,189,919

` METHOD AND APPARATUS `FO1`MATIDN PRESSURE T ESTING Fii'ed July 18.193e \4 sheets-sheet -1 Feb. '13; 1940. A r.`.v. MooRE METHOD ANDAPPARATUS FOR FORMATION`PRESSURE TESTING Filed .my 18, 193e' 4sheets-sheet 24 Feb. 13, 1940.

METHUD AND APPARATUS FOR FORMATION PRESSURE TESTING 4 Sheets-Sheet 4Filed July-18, 1936 llllvlltlll f wraamssaezd WMS mation tester islowered into the well.

Patentedl Feb.l 13, 19x40 Arm APPARATUS Fon FORMATION *massima 'rns'rmeThomas V. Moore, Houston, Tex.,v asslgnor to Standard il DevelopmentCompany, a corpo ration oi'Delaware 'Anuman .my 1s, 199s, serial No.91,254

esclama. (o1. ies- 1) This invention relates to an improved method andapparatus for indicating pressure of la formation tapped by adrill hole.

The invention will be fully understood from s the following descriptiontaken in connection with the accompanying drawings, in which latter-Fig. .-1 is a vertical sectionalview through the earth `surroundng abore hole showing, in longil0 tudinal section, a preferred form ofapparatus for carrying on the invention.

Fig. -2 is a vertical sectional view through the device showing thepressuregauge disposed in the casing labove the sand tester.

Fig. 3 is a diagram showing a rec'ord obtained by the device when theformation tested does not contain fluid under pressure greater thanatmospheric, and i 4 Fig. 4 is a diagram showing a'record obtained 2o bythe device when the formation tested does.`

VII. These passages converge downwardly and they both communicate attheir base with the I linterior of the hollow adjusting sleeve I5. The

adjusting sleeve Ii is connected to a hollow perforated pipe-or strainerIB, which when the` 5 invention is employed totest a well through theemployment of a so-called "rat hole is adapted to fit into the Arat holeand support the sides of the rat hole when the pressure o! themud-ladenl iluid within the well is sealed oil from said hole lill Vashereafter described. The strainer I6 is Iclosed at its lower end by theplug Il. Thepin td is made of greater diameter also in order to betterreceive a packer member I8. The packer mem-1' contain `fluid undergreater than atmosphericv I pressure.

Referring particularly to the drawings, rei'ery ence numeral Idesignates a bore hole orwell,

and 2 designates a formation, such as a sand,-

to be tested. Thebore hole I is drilled to the point', and a hole ofrelatively small diameter,

or rat hole, Bis extended into the formation 2. The hole i', normallycontains drilling mud or other uids during the drilling operation ori'lowing into the well from formations traversed by the hole. p

` In testing theformation 2 to determine the pressure of the fluidscontained therein, a .for-

The formation tester may be such as that disclosed in the U. S. patentto Simmons, No, 1,930,987,

' dated October 17, 1933, entitled Method and apparatus for testing theproductivity of forma- 0 tions encountered ina well.

The dri11irrg`^mud is designated as E.

'Referringv to Fig. l, the formation tester is alxed to thelower end ofa drill pipe.- Ill. ,The formation tester includes a valve at the end ofthe casing II) which can be manipulated as :le-

sire'd\from the surface of the well to close or openithe empty chamberor conduitv constituted by' tli"epipe lor casing I0. The valve comprisesa body`i\\IIv traversed longitudinally Vby one or more passages I2',disposed diametrically o! the s0 body Illtii'he body II is provided withpins I3 and I4 extending respectively upwardly and downwardlyitherefrom. The upper pinA I3ls smaller in diameter than the lower pinI4. `'l'he lower pin I4 traversed by passages which are. l 55continuations of-the passages ,l2 in the body part ber` I8 is indicatedas being of truste-conicalA l5 shape so that it is adapted to wedgewithin the upper end o! therat hole within the well bore, and thus sealthe formation below the pressure of the mud-laden fluid within the well.For this purpose the packer member Il may, for example, A20 be composedof rubber, lead or other appropriate material'.

The upper divergent ends of the passages l2v open at opposite sides ofthe narrow upper pin I3 and these passages are adapted to register 25 I3and is secured'thereto by the lock nuts t2 It wlllbe seen that, there isprovided a valve 0' at the end ofthe casing Il which can be manipulatedas desired from the surface o! the well to close or' open the emptychamber or conduit provided bythe pipe ror casing I 0. The slot 24 andthe pin 25 between the bushing 2l I and the 45 body Il ot the valveprovide a means by which. therelative rotation between the head and bodyof the valve may be limited in order to facilitate registering thepassages in the head with those in the body' of the valve. i i

`In using the apparatus for testing formations'. the valve is firstclosed and the device is lthen let down through thejwell. In o thiscondition any uid that may be standing in the wellwill ,u

be prevented from entering thecasing I0. In V this manner there is thusestablished an empty By separating the drilling fluid and the portion.

chamber or conduit adjacent the formation 2 to be tested, without thenecessity of removing the mud-laden fluid 8 from the well. 'Ihe packerI8 is lowered into the small hole 6 and is forced against the shoulder4, compressing the packer and thereby excluding al1 fluid from the wellabove. The packing member I8 is forced against the shoulder 4sufllciently tightly to separate the column of drilling mud in the borehole I above the packer I8 from the body oi' the 'drilling mud in therat hole 8 trapped beneath the packer Il. It will be understood that thehydraulic pressure of the column of mud-laden uid 8 in the well is verygreat, often in excess of 2,000 lbs./sq. in.

of the hole below the packing member I8 from the column of drillingfluid above thepacking member I 8the weight of the column of liquidabove the packer I8 is removed from the liquid below-the packer I8.

' In view of the high pressures of the column of drilling mud exertedupon the drill pipe III, it is frequently desirable to partially ll thedrill pipe I8 with liquid, such as water or drilling fluid, designated21, to prevent collapse of the drill pipe due to the high pressures.l Itwill be understood that the drill pipe I is not completely filled withthe water 21, but only to a sufllcient height to prevent collapse of thepipe. When the pressures prevailing in the column of drilling mud arenot sufliclently great as to cause dangerof collapse of the pipe, noliquid is disposed within the pipe. The` upper end of the drill pipe isopened to the atmosphere.

For testing the pressures in the hole 6 below the packer member I8, andin the formation 2 ad- Joining the hole, the sleeve I carries a dependying tube I8 perforated as indicated at 80. The

perforated tube 3|l4 contains a deep well pressure gauge 88. The gaugecomprises a drum 84 containing a chart, which are together driven inrotation by. means of clock mechanism 36 for a prolonged period of time,such as 20 hours or the like. The pressures prevailing in the rat hole 8and in the. sand tube to be tested are indicated n upon the chartthrough the following mechanism.

A stylus 88 is suspended within the gauge 38 by means of a piston 89carried by a helical spring 40, and bears against the chart carriedbythe drum 84. The piston 39 passes slidably through a partition 42 in thegauge. The portion of the sauge above the partition 42 communicates withthe exterior of the gauge through an opening 45. As a result, thevstylus 38 is responsive to the pressure exteriorly of the gauge to drawa mark upon the chart proportionate to the pressure outside of thegauge.

The assembled formation tester andv recording gauge are lowered into thehole I, and the sealing member I8 is forced against the shoulder 4. Theclosed lower end of the body portion II is then opened by turning thedrill stem III which opens the valve. The drilling fluid plus the fluidin the formation 2 is under the initial pressure of the column ofdrilling iluid and consequently ows upwardly through the open valve intothe drill pipe I 8. The chart of the pressure gauge 8 8 was set inrotation when the formation tester was first lowered into the. drillhole. The chart, therefore, initially records the increasing pressure towhich the pressure gauge-is subjected as it is lowered through thedrilling fluid to the bottom of the hole. Upon opening the valve member2|, the trapped uid ows into the drill pipe- 0f the productivity of theyformation 2 and the pressure of the fluid surrounding the gauge 38drops. The changing pressures are continuously recorded. The packingmember I8 is maintained against the shoulder 4 for a suitable length oftime tol permit the pressure of the fluid 5 surrounding the gauge 38 toreach an equilibrium position. The valve member 2| is then rotated bythe drill pipe I0 into position to close the valve, after which thecombined formation tester and deep well pressure gauge are drawnupwardly through the hole I. Upon removing the packing' member I8 fromthe hole 6, the gauge again becomes subjected to the pressure of thecolumn of drilling fluid so that a record is obtained of the pressuresof the drilling fluid at various elevations in the well. n

A record obtained where the formation did not contain fluid underpressure is illustrated in Fig. 3, in which the ordinate designates lbs.pressure/sq. in. and the abscissa designates time intervals of tenminutes. Referring to the chart, the line designated A designates theincreasing pressure of the column of mud as the device was lowered intothe well. The line A designates the pressure in a well to a depth of8,545 feet. It will be noted that the pressure of the column of drillingmud adjoining the gauge increased to a pressure of 4,520 lbs./sq. in. at8,545 feet. At the point designated B, the valve member 2| wasopened'and the fluid in the rat -hole 6 and forma- 30 tion 2 flowed intothe pipe 1I0. It will be noted that the trace of the record droppedabruptly. At the point on the chart designated C, the valve member 2|was closed andtheapparatus was drawn upwardly through the well.' Thegauge 35 was thus again. exposed to the pressure of the column ofdrilling fluid which pressure gradually decreasedas indicated on thetrace at D.

Referring to Fig. 4, a record is illustrated taken of pressuremeasurements madein which the for- 40 mation 2 contained fluid undergreater than atmospheric pressure. Arrangement of the record isidentical with that illustrated in Fig. 3. Referring to the record, thetrace designated by A shows that the mud pressure increased to apressure of 4,250 lb./sq. in. at a depth of 8,460 feet. .At this depth,the val've member 2| was opened as indicated at point B on the chart.'I'he trace droppedv oft' abruptly to a pressure of approximately 2,700lbs./sq. in. as the trapped fluid from the portion of the holedesignated 6 l owed into the drill pipe I0. 'Ihe trace shows that as theformation fluids continued their flow into'the drill'pipe for 110minutes, owing pressure increased to a substantially constant level of.3,800 lbs./sq. in. At the point C the valve memy the trace isldesignated E. 'I'he instrument was then drawn upwardly through the welland the trace D shows the pressure reduction recorded by the gauge 88 atthis time. It will be understood that the formation 2 to be tested maybe formed of porous and permeable rock and that the pores may containuid under pressure. `The reduction of pressure as the 7 0@l trappedfluid '-,ows into the drill pipe I8 may .permit of expansion of vaporscontained in the/f formation `uid.v such asf yhydrocarbon vapors wherethe formationliluid is oil. 'Ihen the index.

iszthe 'ls f if quantity of fluid produced per unit of lowering ofpressure and the effect on the formation 2.- The record of pressureobtained gives an indication of thenature or productivity pf the sandbeing tested. Also the record indicates thesuccess or failure of themechanical operations in;`

' volved in making the tests.

While -in the embodiment illustrated in Fig. l, drill pipe i0 is shownas containing liquid 21 under lesser pressure than the pressuresprevailing in the drilling mud outside of the drill pipe i0, to permitof obtaining a differential pressure between the trapped ,fluid and thecontents of the drill pipe, it will b e understood that the drill pipemay be empty of liquid so that the contents of the drill pipe will besubjected to atmospheric pressure. f

In'the embodiment illustrated in Fig. 2, the pressure gauge 33 isillustrated as being supported upon the walls .of the drill pipe i0 bymeans of a suitable bracket or spider 50, at a point above the valvemember 2| any suitable distance, such as from'one to several hundredfeet. Alternatively, the pressure gauge 33 may be located directly uponthe body-of the forma-f' tion tester and some of the advantagesfof theinvention -will lbe retained. In still another modiication of theinvention, it is contemplated to` lowerthe deep well pressure gauge by aline or string of pipe into the drillpipe i0,into a posiv tionimmediately above the valve member 2i so in the `formation 2, and theygivean indication of the productivity of the formation 2, from thepressures maintained during the flow while the valve member 2i is open.Opening of the valve member 2l reduces the pressure 'opposite `the sandor formation 2, thus permitting any fluid l formation tapped by a drillhole containing liquid, which comprises shutting off communication withthe formation of the liquid in the hole at a point above the formation,opening communication of the formation to a pressure less than theformationpressure, and 'recording the pressures occurring in the holeadjacent the formation as flow occurs.

2. 'I'he method of indicating productivity of ya formation tapped by adrill hole containing liquida, which comprises lowering into the hole apipe" having a closed lower end while maintaining fthe upper end of thepipe above the liquid, sealing permit flow of the trapped fluid and anyformation fluid into the pipe whereby the formation and its containeduuid are subjected to reduced pressure. and obtaining a continuousrecord 'of the: pressures exerted by the formation or the fluids`contained therein or issued therefrom.

3. The method of` indicating productivity ofa formation tapped bya'drill hole containing liquid under greater than atmospheric pressurewhich comprises lowering into the vhole a pipe partially filled withliquid and having Aa closed opening the closed lower end tto-peiginit`iiow of the trapped fluid and any formation fluid Viito the pipe wherebythe formation and its con'' tained fluids are subjected to reducedpressure, and obtaining a continuous record of the pressures exerted bythe formation or the fluids contained therein or issued therefrom.

4. Apparatus for indicating productivity of a .formation tapped by adrill hole, which comprises means for shutting off communication withthe formation of any liquid in the hole ata point above the formation,means for opening commu. nication of the formation to a pressure lessthan the formation pressure to permit flow of fluids from the formation,and means for recording the pressures occurring in the hole adjacent theformation as flow occurs. I

5. Apparatus for indicating the productivity of a formation tapped by adrill hole containing liquid,which comprises a pipe having a closedlower end adapted to be lowered into the hole with its upper end "abovethe liquid. means for sealing the pipe against the walls of the hole ata pointv above the formation to prevent communication between theliquids around the pipe r above and below the seal, means for openingthe closed lower end to permit flow of the trapped fluid and anyformation fluid into the pipe whereby the formation and its containedfluid are subjected to vreduced pressure, and means for obtaining acontinuous record of the pressure exerted 'by the formation or thefluids contained therein or issued therefrom. Y

6. Apparatus for indicating the productivityof a formation tapped by adrill hole containing liq-A uid,- which comprises a pipe having a closedlow- 'er end adapted to be lowered'- into the hole with its upper endabove the liquid, means for sealingl the pipe against the walls of thehole at a point above the formation to prevent communication between theliquids above and below the seal, valve means for `opening the closedlower end to permit flow of the trapped iluld and any formation fluidinto the pipe whereby the formation and its contained fluid aresubjected toreduced pressure, and means disposed above the valve meansin the pipe 'for obtaining a continuous record of the pressure exertedby the formation or the fluids contained therein or issued therefrom.

7. Apparatus for indicating the productivity of a formation tapped by adrill hole containing liquid, which comprises a pipe having a closedlower end adapted to be lowered intotheholewith its upper end above theliquid, means for sealing the pipe against the walls of the hole at apoint above the formation to 'prevent communication between kthe liquids.above and below the seal, valve means for openingv the closed lower endto means for obtaining a continuous record of the pressure exerted bythe formation or the duids contained therein or issued therefrom 8.Apparatus for indicating productivity of a formation tapped by a drillhole containingv liquids, which comprises a pipe having a closed lowerend adapted to be lowered into the hole with its upper end above theliquid, means for sealing the pipe'against the walls of the hole at `apoint above the formation to prevent communication between the liquidsabove and below the seal, valve means for opening the closed lower endto permit dow of the trapped duid and any formation duid into the pipewhereby the formation and its contained duid are subjected to reducedpressure, and a perforated tube depending from the-lower end of thepipe, and a recording device contained in the tube for obtaining acontinuous record of the pressure exerted by the formation or the fluidvtherein or issued therefrom.

9. A method of testing an oil well, which comprises lowering into thewell an empty string of pipe carrying a valve and a packer and apressure recording device attached. to the pipe below the packer,setting the packer in the well to seal od the formation to be testedfrom the duid' within the well, opening the pipe with ab valve set topermit duid from the formation to enter the pipe and the recordingdeviceto record the resulting pressure, then closing the valve andremoving the pipe with the recording device to the top of the well.

10. A device for testing well pressure which comprises a packer adaptedto be lowered into a Vwell to seal off the same, said `packer carryingpressure responsive means therebeneath whereby the pressure of the duidbeneath the packer may be ascertainedand means for lowering the said Velements into the well and for removing the the sample and record.y i2.-Amethod oi testing the pressureand prov ductivity of a formation in avwell containing 0111! 1.,; a M seal of! a portion of the well adjacentthe formau same therefrom.

l1. Meansfor obtaining a sample of the duid occurring in the formationof a well bore and for ascertaining the pressure of the duid in theformation, which comprises a string of tubing adapted to be lowered intothe well, a packer at the lower en'd thereof having a passagewayv vtherethrough to communicate with said string of 1 tubing, valve meanscontrolled from the top of the well to open and close the passagewaythrough the packer when the packer is set in the hole, pressurerecording means disposed beneath the packer ,and carried thereby andbeing responsive to the pressure of the duid sealed within the holebelow the packer, whereby a record of said pressure may' be-obtained,and means for -operating the 4 valve means whereby the duid sealedbeneath the packer may be permitted to dow upwardly therethrough andinto the pipe under the pressure of the formation and to be thereafterentrapped, and whereby the' pressure occurring beneath the packer afterthe duid has been entrappedin the drill stem will be recorded by therecording device, after which the string of tubing, the packer and thepressure recordingdevice will be withdrawn from the well with drillingduid involving the insertion of A, single string of pipe into the -wellto make contained which includes lowering a test string .into the wellthrough the` drilling duid with a packer carried by the string and avalve inlet at the lower end of the string closed against the en tranceof duid from the welll and a pressure re-` corder below said valve andpacker, setting the packer above the formation and opening the valve topermit duid from the formation to enter the inlet, making a record ofthe fluid pressure below said packer, closing the valve to prevent thesubsequent entrance of duid from the well through the inlet, making arecord of the duid pressure below said packer after said valve has beenclosed, and then releasing the packer and e, raising the pressurerecorder and the test string with the inlet closed against entranceofduid from the well to remove an entrapped sample. 13. A method oftesting the pressure and productivity of a formation in a wellcontaining drilling duid involving the insertion of only a single stringof pipe into the well to make a test, which includes lowering a teststring into the well through the drilling duid with a packer carried bythe string and a valve lmet at the lower end of the string closedagainst the entrance of duid from the well and a pressure recorded belowsaid valve and packer, setting the packer above the formation andopening the valve to permit duid from the formation to enter the inlet.closing the valve to prevent the subsequent entrance of duid from thewell through the inlet and releasing the packer and raising the pressurerecorder and the test string with the inlet closed against entrance ofduid from the well to remove an entrapped sample, and including the stepof making a. continuous record of duid pressure below said packer duringthe entire productivity testing operation.

14. A method of checking the operation of a formation tester having apipe with a valve at the lower end thereof and a packer to isolate theformation being tested from extraneous pressure including the steps ofoperating said valve and recording the pressure below said valve andsaid packer..

15. VA well testing tool, comprising a packer having a passagewaytherethrough, a tubular drill string connected to the packer andsupporting the same, means normally excluding duid fromthe drill stemand for entrapping a sample offduld from beneath the packer within thedrill string when the packer is set, pressure recording means carried bythe packer and therebe- V neath, and being sensitive to the pressureexisting within the duid beneath the packer, whereby the pressure of theduid of the formation beneath the packer may be recorded while theApacker is set. e

16. A method of testing a well and checking the functioning of aformation tester which comprises lowering into the well an emptystring4A of pipe carrying a valve and a packerand a pressure recordingdevice attached to thepipe below the packer, setting the packer in the`well to seal oif the formation to be tested from the duid within thewell, recording the pressure below said 'valve and said packer with saidrecording device whereby it is simultaneously recorded whether the valveis functioning properly and removing the pipe with the recording deviceto the top of' the well.k

4 17. A method of testing the formation of an# oil well or the likewhich includes the steps of lowering into the well an apparatus adaptedtov areaeie tion being tested and take a sample of fluid therefrom,together with a pressure recording device,

. sealing off the formation being tested from the uid in the well,taking a sample of uid from the formation, recording the pressure duringthe taking of the sample and removing ther apparai tus, sample an'drecording device from the well.

18. An apparatus for testing oil wells or the like which includes meansfor sealing off a portion of the well from the remainder and a pressureindicating device associated therewith and adapted vto indicate thepressure inthe sealed off portion of the well.

19. In combination, a formation tester for a well bore including apacker adapted to seal ofi a formation from the remainder of the bore,`and a pressure recorder below said packer adapted to vbepositionectadjacent said formation to record the pressure thereof whensaid packer is set.

20. A formation pressure tester for a well bore comprising a pipestring, a valve in said pipe, a pressure recorder below said fvalve, apacker above said recorder adapted to seal said recorder into a givenformation in the said well bore,

said recorder being adapted to record the presysure on said formationwhen said valve is opened.

21. Apparatus for testing a well` comprising a string of pipe to belowered into a well having an inlet at its lower end and carrying a`packer adapted to be positively pressed against the walls of theformation to seal oi the same above the inlet, a valve for said inletadapted to be controlled from the top of said well to open and vclosesaid inlet while the packer isseated and a pressureresponsive devicebelow said packer.

22. In combination, a formation tester includ-- ing a vtail piece havingan inlet therein and a packer adapted to seal said tail piece into aformation to be tested,-a tubular casing secured to said tail piece anda pressure recorder in said casing. w1

23. An apparatus for testing an oil well, ccmprising the combination ofa formation tester including a string of pipe, valve packer and inletof' a pressure recording apparatus connected to said inlet and providedwith means for automatically recording the pressure of fluids in theinlet pipe of said apparatus.

'moms v. noone.

